A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
For puzzles based around the game 0hh1, found at 0hh1.com: a grid logic game in which you must deduce which tiles are blue and which are red. Related to 0hn0, which is made by the same people.
For puzzles based around the game 0hno, found at 0hn0.com: a grid logic game in which you must deduce which dots are blue and which are red. Related to the game 0hh1 made by the same people.
Puzzles related to the video game 2048.
For puzzles involving the use of acronyms (where the initial letters of a sentence or paragraph form another word or sentence). Don't use this tag if that would spoil (part of) the solution!
A puzzle in which certain letters, e.g. of each word, line, or paragraph, form a meaningful word or words when put together.
a specific type of riddle that clues the target word by describing multiple, possibly overlapping parts of the word separately. Usually the beginning (prefix), the middle (infix), a…
A mathematical puzzle about the manipulation and solution of equations. General algebra questions are off-topic but can be asked on Mathematics Stack Exchange.
A puzzle related to algorithmics (a main concept in computer science).
Alphametic puzzles involve equations where digits have been replaced with letters.
a game, usually online, involving puzzles and ciphers hidden in mysterious videos, images or audio with a story behind them. Usually it is meant to promote a product.
An anagram rearranges the letters of a word or phrase to produce a new word or phrase.
For puzzles related to or involving animals. This tag is not to be used for questions about animals.
For puzzles involving addition, subtraction, multiplication, or division.
A puzzle that makes use of astronomical knowledge, such as the names and positions of stars and planets.
Puzzles based on the analysis of an audio clip
In a 'blackboard puzzle' a set of numbers is transformed according to certain rules.
For questions related to the puzzle of islanders who can only leave when they deduce the colour of their own eyes.
a game that involves counters or pieces moved or placed on a "board" according to a fixed set of rules.
A Bongard problem usually consists of two sets of 6 boxes, positioned beside each other. The task is to discover a rule that describes the contents of each of the 6 boxes on the left-hand side, but do…
For puzzles involving the card game Bridge. If your question isn't a puzzle but a general Bridge question, it's better asked on our sister site Board & Card Games.
an interlocking puzzle consisting of several three-dimensional pieces that are combined to make one three-dimensional unit.
A puzzle that involves numerical calculations, such as multiplication and addition.
For puzzles centered around playing cards. For questions about card games themselves, visit our sister site Board & Card Games Stack Exchange.
Puzzles involving cellular automatons in a 2D or 3D grid.
A puzzle involving checkerboards: grids of squares alternating black and white in color, most commonly an 8x8 board.
A puzzle that makes use of chemical knowledge, such as the names and atomic numbers of chemical elements. General chemistry questions are off-topic but can be asked on our sister site Chemistry Stack …
A puzzle related to chess. Questions about chess which aren't puzzles are off-topic and should be asked on Chess Stack Exchange.
a simple method of modifying messages to make them unreadable, but still possible to recover. Common ciphers are Caesar, Vigenere, Atbash, and several types of substitution cipher. Other c…
A question about electronic circuits and logic gates.